Gluten-free diet may be a waste of money for some, new research suggests

Gluten-free products can be considerably more expensive than their gluten counterparts -- and they're not lower in calories.

Gluten-free products are everywhere, but many people who buy them are probably wasting their money, according to Italian research released Monday.

The worldwide market for gluten-free products is nearly $2.5 billion, spurred in part by the Internet, alternative medicine and questionable scientists with ties to manufacturers, coauthor Dr. Roberto Corazza of the University of Pavia told msnbc.com in an email.

Gluten is a component of the protein mixture in wheat, rye and barley flour. For people with the autoimmune condition celiac disease, foods that contain gluten trigger the immune system to attack the lining of the small intestine. The only treatment is a lifelong, gluten-free diet. Untreated, celiac disease raises the risk of life-threatening conditions such as digestive tract cancers. About 1 in 133 Americans has celiac disease, according to the Celiac Disease Foundation.

Far more people think they have what has come to be called “nonceliac gluten sensitivity,” Corazza says. Sufferers, in whom celiac disease has been ruled out, complain of a variety of symptoms after consuming gluten, including bloating, abdominal discomfort, flatulence and headache. The problem, Corazza and Dr. Antonio Di Sabatino write in an opinion piece in the Annals of Internal Medicine, is that no one is quite sure what gluten sensitivity is.

“Considerable debate about nonceliac gluten sensitivity has recently surfaced on the Internet, with a sharp increase in forums, patients or patient groups, manufacturers, and physicians advocating a gluten-free diet,” the two write. “Claims seem to increase daily, with no adequate scientific support to back them up.”

Gluten-free diets have become “trendy, fashionable,” says Dr. Alessio Fasano, director of the University of Maryland’s Center for Celiac Research in Baltimore, who coauthored an article about gluten-related disorders Feb. 14 in BioMed Central. “I would say the occasional consumers are the ones who have no reason to be on a gluten-free diet.”

Gluten-free products can be several times more expensive than their gluten-containing counterparts. Part of the gluten-free fad comes from the misperception that the foods are healthier or more diet-friendly. The main health concern is that people cut out all gluten as a way to self-diagnose a sensitivity or celiac disease. But, Corazza notes, it’s impossible to diagnose celiac disease in someone who’s gone gluten-free before being evaluated.

When he sees patients who complain of symptoms after eating bread or pasta, Fasano says, he’ll order a blood test to check for biomarkers of celiac disease and a skin test for the far less common wheat allergy. If necessary, he’ll then perform an endoscopy to look for damage in their digestive tract characteristic of celiac disease.

He was skeptical when he first started hearing about nonceliac gluten sensitivity a few years ago, Fasano says, but he since has come to realize that some sufferers are “severely impaired.” But because doctors aren’t exactly sure what the condition is, it’s difficult to diagnose.

The best-known diagnostic method, Fasano and Corazza say, is a double-blind oral “challenge.” Patients are given drinks with and without gluten and then asked how they feel. Neither the patient nor the doctor knows which is which at the time of the testing. Such tests are expensive and time-consuming, though, Corazza says.

“The bottom line for gluten sensitivity,” Fasano says, “is there are very little facts and a lot of fantasy.”